Brush rigging



C. A. THOMAS BRUSH RIGGING Filed Dec. 3, 1949 Inventor Ch arles A.Thomas,

His Attrney.

Mas euse 2,532,821 BRUSH BIGGING Charles A. Thomas, Fort Wayne, Ind,aeeignor to General Electric Company, a corporation at New YorkApplication Deemed- 1.4,, Serial No. 130,910

Claim.

1 Thisinventionrelateatoabrushrigginsiordynamoelectricmachinesandmoreparticularlytoabrulhriggingadaptedtoapplybothlongi-Itis,thereiore.anobiectoithisinventiontoprovideanimprovedbrushflsalngi'ordynamoelectricmachinee.

Another object oi thi invention is to provide an improved brush riggingior dynamoeleciric machines wherein brush chattering is reduced.

'Ainrtherobiectoithlsinventionlstoprovide an improved anti-chatter brushrigging i'or dynamoeiectric machines adaptable for either di-'reetimioi'rotationwhereinthesidepressureis function of the longitudinalbrush pressure. Purtherobiectsandadvantagesoithisinvenwillbecomeapparent and this invention will betterimderstoodiromtheiollcwingdescripreterring to the accompanying drawings, the ieatureso! noveltywhich characterize invention will be pointed out withparticuwintheclalmsannexedtoandiorminga oithkspecification.

aecordancewithoneaspectoithisinventhere is provided a brush guidingmember sali ig memberiaprovidedwithtwosidewallsandanendwalliorminganopensloti'or guiding of the guiding member. A spring isprovided arranged with its ends engaging both levers tor biasing thefirst lever to resiliently urge the brush toward the commutator and forbiasing the second lever to resiliently urge the brush against the endwall of the guiding member for preventing chattering.

In the drawing, Fig. l is a side elevational view, partly in section,illustrating an embodiment of this invention; Fig. 2 is a vertical viewof the embodiment 0! Fig. l; and Fig. 3 is a side elevational view,partly in section illustrating a modification of this invention.

Referring now to Fig. 1, there is shown a stationary brush 881 8 yokemember I surrounding a commutator I. The yoke member I may be secured tothe stationary frame oi. the dynamoelectric machine in any suitablemanner and may be arranged for limited rotation toprovide for shiftingthe brushes. A brush guiding member generally identified as I is mountedon the yoke member i and is formed with side walls I and I and an endwall I defining an open slot 1. The brush guiding member I is secured tothe yoke member I by a, suitable stud I pro- Jecting through side wallsI and I. The open slot I, which is adapted to guide a brush I forlongitudinal movement toward the current collector I, has its Op ningparallel to the axis of the current collector 2.

In order to provide for urging the brush I against the current collector2', a lever member v II is provided having a hub portion ll pivotallymounted on the yoke member I by a stud ii. The lever member II has anarm portion II with a roller it mounted on the end thereof arranged inengagement with the end it of the brush I remote from the currentcollector 2. Arm portion II is preferably ofi'set, as best shown in Pig.2, so that it will bypass lever II. To provide for the application ofsidewise pressure on the brush I for the prevention of chattering,another lever member II is provided having a hub portion ll pivotailymounted on an extension II of the side I oi the brush guiding member Iby a stud II, which in turn is mounted on the yoke member i. The levermember It has an arm portion 20 having a roller 2| mounted on the endthereof engaging the side 22 of the brush I remote from the end wall 6of the brush guiding member I. In order to provide for biasing the levermembers I I and II to resiliently urge the brush I toward the currentcollector I and against the end wall 6 0f the brush guiding member I, acoil spring 21 is arranged on the hub portion ll of the lever II and hasan third lever member 21 mounted on the yoke member I in the same axisend 24 engaging arm portion I; of lever II. The other end 25 of the coilspring 22 is arranged in sliding engagement with a convex surface 2' .ofthe arm portion 29 of the lever member it. Thus, the spring 29 appliespressure on the levers II and it to bias the lever Ill so that the brush9 is resiliently urged, toward the current collector 2 and to bias thelever It to resiliently urge the brush 9 against the end wall 6 of thebrush guiding member 3 to prevent chattering. On larger brushes, asshown in Fig. 1, it has been found desirable to angle the top I! of thebrush by a small amount, for instance, 10 or less, in order to preservestability of position. However, it will be readily understood thatbrushes with a flat top surface can be utilized. Stop pin 92 is providedfor the arm 20 to limit its travel so as to facilitate the insertion ofbrushes.

Referring now to Fig. 3 in which like parts are indicated by likereference numerals, a is provided pivotally as the lever member ill bythe stud [2. The lever member 21 has an arm portion 29 having a roller29 mounted at the end thereof arranged in engagement with a surface 30of the arm 20 of lever member ii. The spring 23 has one end 24 engagingthe arm portion l3 of lever l9 and its other end 3| engaging the armportion 28 of lever 21. Thus, the spring 23 in the embodiment of Fig. 3applies pressure on the levers l9 and 21 so that the lever III is biasedto resiliently urge the brush. 9 toward the current collector 2 and thelever 2'! is biased to resiliently urge the lever 20 against the side 22of the brush 9 so that the brush 9 is resiliently urged against the endwall 8 of the brush guiding member 9 for preventing chattering.

'It will now be readily apparent that this invention provides animproved brush rigging wherein chatter-preventing side pressure isapplied on the side of the brush for both directions of rotation, theside pressure being a fraction of the longitudinal pressure so that theside pressure decreases with a decrease in the longitudinal pressure.

While I have illustrated and described a particular embodiment of thisinvention, modifications thereof will occur to those skilled in the art.I desire it to be understood, therefore, that this invention is not tobe limited to the particular arrangement disclosed,'and I intend in theappended claims to cover all modifications which do not depart from thespirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A brush rigging for a dynamoelectric machine having a currentcollector comprising a yoke member surrounding said current collector, abrush guiding member mounted on said yoke member having two side wallsand an end wall forming an open slot for guiding a brush forlongitudinal movement toward said current 001- membersfor biasing saidfirst-mentioned lever member to resiliently urge said brush toward saidcurrent collector and for biasing said lastmentioned lever member toresiliently urge said second-mentioned lever member against said side ofsaid brush whereby said brush is resiliently urged against said end wallof said brush guiding member for preventing chattering.

2. A brush rigging for a dynamoelectric machine comprising a brushguiding member having an open slot formed therein for guiding a brushfor longitudinal movement toward said current collector, a lever memberadapted to engage the end of said brush remote from said currentcollector, a second lever member adapted to engage a side of said brush,a third lever member adapted to engage said second lever member, and aspring having its ends respectively engaging said first-mentioned andsaid third lever members for biasing said first-mentioned lever memberto resiliently urge said brush toward said current collector and forbiasing said third lever to resiliently urge said second lever againstsaid side of said brush whereby said brush is resiliently urged againsta wall of said brush guiding member slot for preventing chattering. 1

3. A brush rigging for a dynamoelectric machine having a stationarymember comprising a brush guiding member having an open slot formedtherein for guiding a brush for longitudinal movement toward a currentcollector of said dynamoelectric machine, a lever member having a hubportion pivotally mounted on said stationary member of saiddynamoelectric machine and an arm portion having a roller arranged onthe end thereof adapted to engage the end of said brush remote from saidcurrent collector, a second level member having a hub portion pivotallymounted on said stationary member and an arm portion having a rollerarranged on the ;end thereof adapted to engage a side of said brush, athird lever member having a hub portion pivotally mounted on the sameaxis as said first-mentioned lever and an arm portion having a rollerarranged on the end thereof adapted to engage said armportion of saidsecond lever member. and a spring arranged on said hub portion of saidfirst-mentioned lever and having its ends respectively engaging said armportions of said first-mentioned and third lever members for biasingsaid first-mentioned lever member to resiliently urge said brush towardsaid current collector and for biasing said third lever to resilientlyurge said second lever against said side of said brush whereby saidbrush is resiliently urged against a wall of said aruislh guiding memberslot for preventing chat.-

4. A brush rigging for a dynamoelectric machine having a stationarymember comprising a brush'guiding member having an open slot for guidinga brush for longitudinal movement toward a current collector of saiddynamoelectric machine, a stud mounted on said stationary member, alever member pivotally mounted on said stud, a second lever memberpivotally mounted on said stationary member, and a coil springsurrounding said stud and connected at its respective ends to saidlevers and operable in torsion to maintain a uniform ratio of pressureson said levers for biasing said first mentioned lever member toresiliently urge said brush toward said current collector and forbiasing said second-mentioned lever member to resilientassasav 8bmshagainstawallotsaidbruah berior prevenflng chattering.

rigging tor a dynamoeleetric maa stationary member eomprisinsbnmhguidingmemberhavinganopenslotior guidirq a brush for longitudinalmovement tocurrent collector oi said dynamoeleetric alever member havinga hub portion on said dymmoeleetric maan arm portion adapted to endisaidbrush,theouterend chine. a lever member having a hub-portionpivotally mounted on said stationary member of said dynamoeleefi iemachine and having anarmportionadaptedtoengagetheendoi said brush remotefrom said current collector, another lever member pivotally mounted onsaid stationary member having an arm portionadapicdtocnslgcasideofsaidbrusnthearm portion 0! said first-mentionedlever being oiiset so as to bypass said second-mentioned lever, andaspringmemberhavingoneendccnneetedto the arm portion of first-mentionedlever memberanditsotherendcnxazingthearmportion or said second mentionedlever member wherebysaidspringisoperabletomaintainauniiorm ratio ofpressures on said lever members for biasing said first-mentioned levermember to resiliently urge said brush toward said current collector andfor biasing said last-mentioned lever member to resiliently urge saidbrush I against a wall of said brush guiding member slot for preventingchattering.

CHARLES A. THOMAS.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATE PATENTS

